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But that's not the only point of the Promise vs. Observable debate. Just pick the right tool for the job.
I found this great list on StackOverflow on when to use one over the other; maybe it's helpful to you.
Use Promise instead of an Observable, when:
You need to handle the (future response) event no matter what (no unsubscribe, no cancel: after you subscribe, there will be an answer, 100%, and you will have to handle it, 100%, the code will get executed)
One SubscriptionSubscription = One Event handling: there will be only one event from the source, so the future response and the completition is the same event.
Use Observable instead of a Promise, when:
You want to have the ability to accept multiple events from the same source
You need a "I am finished with this event stream" handler
You want to be able to unsubscribe from a possibly never ending stream of data, and re-subscribe anytime (meaning also that you might don't really need to fulfill the SubscriptionSubscription at all: for instance, if nothing happens in 10 sec, let's unsubscribe, nobody will ever handle the late answer)
You want to use the RxJS "Stream API" to preprocess the data of your responses.
Generally, the Observable pattern is an extended Promise pattern, with a lot more tools and functionality. It is up to you to decide to limit the code with Promises or not. It was first a custom libary, then got included in ES2016.
My main job is not in IT, but I do have a CS degree and have been programming for over 20 years (only born in 1984). I hate dealing with Servers, and want Graph Databases to be the new norm.
Everything seems to be in Observables in Angular, so after a little experience, you get good at going between the two for your needs. I think it helps you master async techniques in general. I tend to use .pipe(take(1)).toPromise(); all the time, but never go from Promise to Observable. As you said, they have different uses, depending on the data source.
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When I read the post, I can't find actual evidence in what way Observables are faster.
A person on StackOverflow has run a great test to measure the performance of a Promise and Observable. There you can see that a Promise is more performant than an Observable.
But that's not the only point of the Promise vs. Observable debate. Just pick the right tool for the job.
I found this great list on StackOverflow on when to use one over the other; maybe it's helpful to you.
Use Promise instead of an Observable, when:
Use Observable instead of a Promise, when:
Source: StackOverflow
The test right under that, which to me reads as a better test anyway: Observable wins.
Everything seems to be in Observables in Angular, so after a little experience, you get good at going between the two for your needs. I think it helps you master async techniques in general. I tend to use
.pipe(take(1)).toPromise();all the time, but never go from Promise to Observable. As you said, they have different uses, depending on the data source.